CVE-2020-6806

critical
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
9.5

Description

By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of an array resized during script execution. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-6806

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2020-6806.html

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202003-8

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202003-11

OS impact

OSVersionStatusFixed in
arch archfixed68.6.0-1
suse slesaffected
debian debiansidfixed74.0-1
debian debianbookwormfixed68.6.0esr-1
debian debianbullseyefixed68.6.0esr-1
debian debianforkyfixed68.6.0esr-1
debian debiantrixiefixed68.6.0esr-1

References

Verify integrity in audit chain (admin only). AS-IS.